Horizontal retort with reciprocating agitator



Oct 28, 1952 F. E. POINDEXTER Er AL 2,615,834

HORIZONTAL RETORT WITH RECIPROCATING AGITATOR Filed Aug. 2, 1948 3 Sheets-Sheet 1 HIS ATTORNEYS.

0t- 28, 1952 F. E. POINDEXTER Er AL 2,515,834

HORIZONTAL RETORT WITH RECIPROCATING AGITATOR Oct 28, 1952 F. E. PolNDExTl-:R Er Al. 2,615,834

HORIZONTAL RETORT WITH RECIPROCTING AGITTOR l 3 Sheets-Sheet 3 Filed Aug- 2, 1948 FIG.

Eatented ct. 28, 1952 HORIZONTAL RETORT WITH RECIPROCATING AGITATOR Franklin E. Poindexter, Richmond Heights, and Frank W. Lowe, St. Louis, Mo.

Application August 2, 1948, Serial No. 42,066

8 Claims.

This invention relates to the distillation or carbonization of coal or other distillable or carbonizable materials and is more particularly directed to a means and method for distillation at low temperatures,

Heretofore in many of the methods for the distillation or carbonization of coal or other distillable materials it has been customary to charge a, retort with a quantity of material and then heat it to a high temperature to obtain char and all the other products of distillation. During the operation heat is supplied to the material until distillation is more or less complete, resulting in low overall heat efficiency, impurity of distillation products and the decomposition of various valuable oils and gases into less desirable products.

One of the objects of this invention is to provide a retort for distillable material containing a heated plate and which incorporates means for repeatedly lifting from and exposing the material to the plate as it is traversed thereover.

Another object of the invention is to provide a retort having a plate therein heated to difierent temperatures in diflerent portions thereof over which the distillable material is passed so as to subject it to varying temperatures as it passes thereover and which includes means for rapidly and successively removing and applying unprocessed material to the heated plate.

Still another object of the invention is to provide a retort that is flexible as to temperature control zones and as to the rate of passage of the material being charred through the retort.

Another object of the invention is to provide a char briquetting manufacturing method which utilizes the char remaining after the volatile products have been distilled from the coal, which method involves the use of a mixture of tar and dust derived from the coal.

A further object of the invention is to provide a method of processing char into briquettes which utilizes some of the waste products of coal distillation and which recovers a substantial portion of the heat used in the distillation and briquetting process in heat exchangers for further use.

A still further object of the invention is to provide a mechanism for distilling coal or other distillable material at low temperatures in order to remove numerous desirable products of distillation and to recover these desirable products in purer form for various commercial uses.

In the drawings:

Fig. 1 is a schematic illustration of a system for charring and briquetting,

Fig. 2 is a vertical longitudinal sectional View 0f the distillation retort,

Fig'. 3 is an enlarged sectional view of the intake end of the retort,

Fig. 4 is a vertical sectional View taken substantially along the line 4-4 of Fig. 2; and

Fig. 5 is a showing of a symmetrical style of stirring blade.

The charring of coal, peat, wood, lignite, oil shale and other carbonizable material is accomplished by introducing it in pulverized or nely divided form into a retort I at its intake 2, the structural details of the retort to be subsequently described. The retort I is pivotally supported at 3 on a suitable framework 4 and the tilting of the retort is accomplished by levers 5 (only one of which is shown), one end of which is pivoted to the framework 4 at 6 and whose opposite end is provided with a series of spaced apart perforations 'I in which are insertable suitable pins 9 (only one being shown) xed in the frame 8 constituting a base for the retort I. The entire assembly is easily transportable so that it can be readily moved to sources of material to be treated or processed.

The retort I is heated to the desired temperature by means of a plurality of gas burners I0. The gases, dust and vapors formed during distillation are drawn oif through a suitable duct II, connected to the interior of the retort I, by a pump I2. Before reaching the pump I2, dust laden tar is collected in catcher I3. The lighter oils are condensed in condenser I4 and the remaining gases then pass to pump I2, some of the gases being used to supply burners I0 and the remainder being disposed of in any suitable manner. The oils collected in condenser I4 are separated by further processing to place them in their most desirable salable condition.

The char is discharged from the retort I through exit duct I5 and since it is at a temperature high enough to burn, it is first passed through heat exchanger I6 in the form of a boiler in order to recover the heat in the char and use the steam from'the heat exchanger for power or other purposes.

The cooled char then passes from the heat exchanger Io, by means of duct I'I, to mixer I8 Whose tubular body is rotated on its longitudinal axis by gear means I9 operated by a suitable prime mover (not shown). The interior ofthe mixer body is provided with suitable stirring means so that dust laden tar derived from chamber |3 will be mixed with the char. The chambers in mixer i8 and in catcher I3 are connected by conduit 2G in which a suitable pump 2| is interposed. The dust laden tar is introduced under pressure into the mixer I8 by pump 2|. Suitable outlet ports 22 are provided in the mixer through which the mixed tar, dust and char is led into a briquetting machine 23 where briquettes are formed. The briquettes are then admitted to a caking furnace 24 to harden them preparatory to storage and shipping. The tar vapors that emerge from furnace 24 are returned to the'xtar catcher I3 for condensation and reuse. The briquettes are heated in caking furnace 24 above the kindling point, and, upon emerging, are cooled in heat exchanger 25, that is preferably in the form of a boiler Whose steam or hot water is available for useful work. When emerging from the heat exchanger, the briquettes have been cooled below the kindling point and are `carried away to storage bins on conveyors 26. The mechanism described recovers a maximum of the heat employed for coal distillation purposes and that used in caking the briquettes made from the char discharged from retort I.

The structural details of retort I are disclosed in Figs. 2, 3, and 4. The frame 8 supports a hot plate 30 heated by the plurality or" burners |63. This plate is preferably made from copper or a chrome steel. If copper is selected, or any other metal that softens at low temperatures, it is supported by a plurality of structural members 3| (Fig. 3), the plate being supported at its edges by brackets 32 (Fig. 4) forming part of the side walls 33 of retort I. rThe frame 8 supports a bottom wall 35 upon which rests a structural member 311 that supports the structural members 3|, with the gas burners I0 being supported on structural member 34. A gable roof rests upon the walls 33 into which outlet ducts 36 are fitted, the roof being made up of two insulated wall sections 3l, the ducts 3e being connected to duct The side brackets 32 have tracks 38 formed thereon and the tracks, in conjunction with the side wall, form the collecting troughs 39 that extend the entire length of the retort. The tar troughs drain into collecting vessels 40 through conduits 4|, the latter having traps formed therein.

The tracks 38 support carriage frames 42 on a plurality of wheels 43, each pair of the latter being connected by a rod 4Q. A plurality of spindles 45 are connected between each of the carriage frames and freely rotatably supported on each of the spindles is a scraper 45 that extends across the entire distance between the frames and consequently the major portion of the heated plate 3B. Each scraper is provided with a curved or concave forward face 41 closely approximating that employed on one type of snow plow. The rear face 43 is a plane surface that diverges in the manner shown toward the spindle 45 so as` to enable the scraper to be drawn underneath the material being processed. The rear face 48 may be curved, if so desired as shown in Fig. 5, in the same manner as face 41.

The right hand end of the scraper and carriage assembly has a rod 49 connected thereto that is slidable in a bearing B. The rod 49 is connected by means of connecting rod 52 to a crank wheel 5| rotatably supported on the frame 8 and a track mounted counterpoise 53 is suitably connected to the crank wheel 5I at a point opposite the crank pin connection for rod 52 so 4 as to counterbalance the action of the scraper assembly. Crank wheel 5| is driven from a suitable variable speed prime mover (not shown).

The bearing 58 is received in a housing 54 that constitutes a closure for one end of the retort I and in which the inlet 2 is supported. The housing 5d is supported on frame 8 by means of a bracket 55 that also supports structural member 34. The housing 54 is provided with a tapered surface 56 that delects material to be processed into the retort and also protects rod 49.

The opposite end of the retort is equipped with a closure 5l supported by a bracket 53. The closure 51 also supports outlet duct i5 which, in turn, supports the left hand end of structural member 34. The lower end of the outlet duct is closed by a trap door 59 pivotally supported thereon and normally maintained in closed position by counterweight 50.

Each of the gas burners Il) is individually controlled byv valves 6| by means of thermostatic elements E2, the two being connected together by means of suitable connections well known in the art. The thermostatic elements are adjusted so that plate 30 is supplied with a graduated heat from one end to the other, thereby providing different heat zones in the retort and holding the temperature of the material at a substantially uniform rate in each zone but not to exceed the distillation temperature.l

Coal in nely divided form is admitted to retort I through intake 2 and falls onto the surface 56 and is deflected onto the hot plate 30. The coal or other material lls the intake 2 and prevents escape of gas and other volatile substances. The crank wheel 5| is set in operation to reciprocate the scraper carriage and coal is permitted to now toward outlet I5, it being understood that retort I is tilted at a proper angle to facilitate the ow of material. The coal covers the scraper mechanism to a depth slightly greater than the height of each scraper. The plate 38 is brought up to the desired temperature in its initial Zone to about 1000" F. and is held at this temperature throughout the successive zones as it progresses toward outlet I5 although lesser amounts of heat are applied to each succeeding zone of the plate. This temperature approximates that needed for most coals but the plate temperature must, in any event, be brought up to at least the minimum value necessary for any given material. The curved face Ii'I of scraper 46 on the forward stroke, removes hot material from the plate and lifts it upward onto and into the unprocessed material which replaces that removed. The timing or rate of operation of the scraper is such that the coal that contacts the plate remains only long enough to become heated. The tilt of the plate and the operating speed of the scraper, singly or in combination, determines the rate at which coal moves through retort I.

Coal has a very low heat conductivity factor and, therefore, when heated will retain it. Unless stirred, considerable time elapses before all the coal in a given layer is heated. AThe scrapers 46 are, therefore, rapidly operated, preferably four times per second at least, so that all parts of the layer of coal will contact the plate to become heated. This act prevents excessive heating of any one part of the coal and will bring the entire layer gradually up to the desired distillation temperature. None of the distilled vapors or the residue is heated to or comes into contact with a surface that is hotter than that required to distill said vapors. Oils and gases are distilled e out, preferably during the latter part of the travel Our hot plate is 15 sq. ft. in area.k So we have of the coal, at which time the entire mass of coal reaches the distillation temperature. Also, w22/i0() uga/hn by agitating the coal, the layer of char on each 1000 particle is removedz therefore, exposing the in- 5 carbonzed' assuming terior of each particle or piece of coal directly to the plate 30, thereby expedting the distilla- 1000 tion process. During the return stroke of the 1bscraper, the diverging face 48 enables the scraper to slide under the coal contacting the plate, there- Below 1S listed four coals We have run and. in by additionally agitating it. The combined aeeach Case 0111 me 0f through-PUF Was Ove? 1 tion of the two scraper surfaces, therefore, negaton/ Thls checks our calculatlons and as' tives the poor heat conducting quality of the coal. Sumptlon as to The layer of coal is comparatively thin and being 1000 B. t. u. repeatedly exposed to the plate after surface 1b,

Volatility Run Made For* Name of Coal reoisved Vflzthiiiliiy Paitriielsehize Diif coal Percent Percent Wilier WStegvenson, 2l7 Sulmeyside (Utah). 43.6 14.9 not ground- 2/18/50 Wallgeyvif. Stevenson, 2l7 Castlegate (Utah) 43 10.7 approx. all 2/18/50 Bway,N Y throlugh l0 Consolidated Coal Co., St. Ill. No. 6 45 14. 6 allnttlisrough 28 5/8/50 Louis. mesh. Old Ben Coal Co Ill. No. 6 32. 55 11 .50% through 2/21/51 (dry) 20 mesh.

char is removed, materially accelerates the car- Another use for the char is as steam boiler bonizing proeess fuel since it can be blown directly from the out- Tar may condense on the inner walls of the let of the retort l (Fig. 1) into the re box of roof member 37 and flow into troughs 39 to be a boiler. collected in vessels 4i). The gaseous substances 35 The machine and the method in which it treats and dust, as previously stated, are drawn from material is employable generally Where distillable retort I by pump I2 with dust laden tar vapor substances are to be removed from a mass of collected in catcher I3. The other gases and oils material, e. g., in the cement industry. The proceed to condenser I4 where the oils are conresidues from those materials, after having the densed, the remaining gas passing out to and 40 heat of distillation removed in a suitable heat through pump I2, exchanger, are then processed in accordance with By employing lower temperatures there is no customary practices in the particular industry appreciable decomposition of the gases and oils relating thereto. distilled from the coal, these products very fre- What we claim is: quently being more valuable than those produced 1. A retort mechanism comprising a longituby decomposition. The tar distilled into vessels dinally extended housing, an elongated charring 4B is comparatively free from carbon, rendering plate having high heat conducting properties it more Valuable and useful. The char remainmounted in said housing, means for applying ing after the coal distillation operation is comheat to said plate, means for introducing pulverplete, drops into outlet I5 and is briquetted, as 50 ized material to be charred onto said-plate, means described above, or it may be consumed as such for elevating one end of said housing for assistif so desired. The tilt of the retort, the rate of reing in determining the rate of movement of the ciprocation of the scraper, and the temperatures material through the retort, means for rapidly are all controlled so that each may be adjusted stirring and moving said material Over Said plate for the shortest period of processing that will which includesareprating C021 agitatOl c0111- extract the maximum of products in their most prising a series of transversely extending scrapdesirable and useful form. ing devices, each device having a substantially 1f We take the time, concave forward face and having a rearward face inclined upwardly away from the plate toward t: 1 hr; 60 the concave face, said scraper devices moving in 20,000 contact with said plate on both strokes, and exas in the ease vof our small plant 11/2 ft. x 1c ft. @151mg Substantially into the layer of coal for het plate, which is the actual time between stirhfimg and ajl'atin the heated material in conrngs' We have tact with said plate, olf said plate and allowing unhattld tisfnalizerialftirihreplafe the heated material 1 B t,u on o s ro es o e agi ating means and ad- 11401/ m=114d -007 =7 .Q8 --r- Vance the layer on each cycle materially less than ft- 20000 hl'- the length of the forward stroke, and means for imposing the reciprocating motion on said coal or agitator.

B t ,1 2. A retort mechanism comprising a housing, 7 .98 20,000=159,600 fm1- means for pivotally supporting one end of said housing, an elongated charring plate in said housor 140 times the heat transfer when no stirring ing having high heat conducting properties, is done. means for applying heat to said plate, means fory on onesside thereof and having a rearward face inclined upwardly away from the` plate and toward the concave face, said faces lifting the coal from said heated plate on both strokes and advance the layer on each cycle materially less than the length of the forward stroke, and counterpoise controlled means for rapidly reciprocating said carriage means for repeatedly permitting coal particles to contact said plate.

3. A retort mechanism comprising an elongated housing, a support therefor to which one end of said housing is pivotally secured, means for controlling the elevation of the other end of said housing; an elongated charring plate having high heat conducting properties in said housing, means for heating saidplate, means for introducing coal particles onto said plate, a track-V to contact the heated plate and for advancingthe layer on each cycle materially less than the length of the forward stroke, means for reciproeating said coal agitator at a high rate of speed to permit the coal particles to repeatedly contact said plate; and a counterpoise operatively connected to said last mentioned means for stabilizingthe high speed action thereof;

4. A retort mechanism comprising an elongated: support, an elongated housing provided with a. sloping cover and having one end thereof pivoted to said sup-port, means for changing the vertical position of the other end of said housing, an elongated charring plate in said housing,

means forintroducingcoal particles onto one end` of said plate, a trough at each` side-of said charring plate, a reciprocating coal agitator comprisinga series of transversely extending scraper blades tiltably mounted on said agitator for movement in contact with` said plate en both strokes, each blade extending substantially into the layer of coal and having a concave cutting face on one side thereof and a plane cutting face on the other side thereof for scraping, stirring and lifting heated coal from the plate during both forward and reverse strokes and to agitate the layer of coal for advancing the layer on each cycle-materially less than the length of the forward stroke, and means for reciprocating the agitator at a high rate of speed over. the charring plate for repeatedly subjecting theA coal particles to said plate, the tar removed from the coal condensing on said sloping cover and collect-ing in said troughs.

5. A retort mechanism comprising a longitudinally extended housing, an elongated charring plate` having high heat conducting propertiesV mounted .in said housing, means forapply-ingheatt0 said plate, means; for intrmus:ineK pulverzed material Arto,- be,` charred onto saidplate, meansv for elevating one end of said housing'for assisting in` determining the rate of movement of thematerial through the retort, a reciprocating agitator means-for rapidly stirring and moving said material over said plate which includes a series oftransversely extending-scraping devices, eachl der to uniformly heat all of the material, said devices moving in contact with said plate on both strokes, means for supporting said agitator meam for reciprocating motion over said plate; and meansfor imposing the reciprocating motion on said agitator means.

6-. A retort mechanism comprising a housing, means for pivotally supporting one end of said housing, an elongated charring plate in said housing and havingV high heat conducting properties, means for applying heat to said plate, means for regulating theamount of heat applied to different portions of said plate, means for introducing coal particles onto said plate, reciprocating agitator means for scraping and lifting coal from said plate for enabling unheated coal to contact said plate, said means including a series ofl transversely extending stirring and scraping blades projecting substantially into the layer of coal and moving in contact with said plate on both strokes, cach blade having a concave cutting face on each side thereof, carriage means reciprocably mounted in said housing in which said agitator means is supported; means for tilting one endV or" saidy housing for regulating the rate of movement of the coal over the plate, said agitator blades advancing the layer on each cycley materially less than the length of the forward stroke, and counterpoise controlled means for rapidly reciprocating said carriage means for repeatedly permitting coal particles to contact said plate.

7. A retort mechanism comprising a longitudinally extended housing, a charring plate in said housing, means for introducing coal onto one end of said plate, means for heating said charring plate, carriage means mounted in said housing for reciprocating movement longitudinally thereof, av plurality of transversely extending agitating Scrapers supported in saidy carriage for movement in Contact with said plate on both strokes, each scraper including symmetrical concave cutting blades on each side thereof extending substantially into the layer of coal for advancing the layer on each cycle materially less than the length of the forward stroke, means for vertically adjusting one end of said housing for tilting the charring plate, and means for rapidly reciprocating said'carriage means to reciprocatesaid Scrapers.,

8. A coal carbonization retort including, a tiltable coal charring member, means for heating one side of said member, coal feed chute means to feed coal to the other side of said member for contact with the heated surface of said member, a reciprocating coal agitator comprising a series of transversely extending Scrapers each having concave cutting blades on each side, said Scrapers moving at a high rate or" speed in contact with the surface of said coal charring member on both strokes, and extending substantially into the i layer of coal, and arranged to lift the coal from the heated surface of said member on both strokes and to agitatethe layer with advancement of the layer on eacli cycle materially less than the length of the forward stroke.

FRANKLIN E. POINDEXTER.

REFERENCES CITED The following references are of record in the fue of this Ipatent:

UNITED S'JIATES PATENTS Number Naxlhe Date Peck Feb. 12, 1901 Number 10 Name Date Priolean Aug. 14, 1917 Smith Aug. 20, 1918 Johns Aug. 22, 1922 Holmes Apr. 10, 1923 Thomas May 8, 1923 Smith Jan. 22, 1924 Debauche Feb. 11, 1930 McIntire Aug. 5, 1930 Loebell Feb. 20, 1934 Russell Dec. 26 1944 

6. A RETORT MECHANISM COMPRISING A HOUSING, MEANS FOR PIVOTALLY SUPPORTING ONE END OF SAID HOUSING, AN ELONGATED CHARRING PLATE IN SAID HOUSING AND HAVING HIGH HEAT CONDUCTING PROPERTIES, MEANS FOR APPLYING HEAT TO SAID PLATE, MEANS FOR REGULATING THE AMOUNT OF HEAT APPLIED TO DIFFERENT PORTIONS OF SAID PLATE, MEANS FOR INTRODUCING COAL PARTICLES ONTO SAID PLATE, RECIPROCATING AGITATOR MEANS FOR SCRAPING AND LIFTING COAL FROM SAID PLATE FOR ENABLING UNHEATED COAL TO CONTACT SAID PLATE, SAID MEANS INCLUDING A SERIES OF TRANSVERSELY EXTENDING STIRRING AND SCRAPING BLADES PROJECTING SUBSTANTIALLY INTO THE LAYER OF COAL AND MOVING IN CONTACT WITH SAID PLATE ON BOTH STROKES, EACH BLADE HAVING A CONCAVE CUTTING FACE ON EACH SIDE THEREOF, CARRIAGE MEANS RECIPROCABLY MOUNTED IN SAID HOUSING IN WHICH SAID AGITATOR MEANS IS SUPPORTED; MEANS FOR TILTING ONE END OF SAID HOUSING FOR REGULATING THE RATE OF MOVEMENT OF THE COAL OVER THE PLATE, SAID AGITATOR BLADES ADVANCING THE LAYER ON EACH CYCLE MATERIALLY LESS THAN THE LENGTH OF THE FORWARD STROKE, AND COUNTERPOISE CONTROLLED MEANS FOR RAPIDLY RECIPROCATING SAID CARRIAGE MEANS FOR REPEATEDLY PERMITTING COAL PARTICLES TO CONTACT SAID PLATE. 